The main objective of this proposal is to study the human T cell antigen receptor molecules through serological and biochemical means. One preliminary results on T cell antigen receptor, and those obtained by others, suggest that this molecular should be polymorphic so as to perform the recognition of different antigens by various T cell clones. We are currently engaged in isolation of sufficient amounts of the T cell receptor molecules from two T cell lines and cells of two patients with T cell leukemia which would allow us to develop reagents directed at the constant portion of these molecules. These reagents will be used for isolation and biochemical characterization of T cell receptor molecules from various sources. These reagents will also prove valuable in pursuing the questions related to the mechanisms of expression of the genes coding for T cell antigen receptor in different subpopulations of normal T cells and T cell malignancies. More specifically, we will utilize obtained reagents for the following purposes: 1. Generation of antibodies against constant region of human T cell receptor molecules. 2. Initial biochemical characterization of T cell receptor molecule isolated from various T cell sources (MW, pI, presence of disulfide bonds). 3. Determination of cell surface components closely associated with T cell receptor. 4. Study of biosynthesis and processing of T cell receptor polypeptide chains isolated from various T cell sources. 6. Characterization of carbohydrate composition of T cell receptor polypeptide chains.